Method for measuring parameters in ultrasonic image and ultrasonic imaging system

ABSTRACT

A method for measuring parameters in an ultrasonic image, includes: obtaining a pelvic ultrasound image, wherein the pelvic ultrasound image is acquired by receiving ultrasound echoes from a pelvic floor tissue with an ultrasound probe and contains an area representing the pelvic floor tissue; displaying the pelvic ultrasound image; determining a position of an inferoposterior margin of symphysis pubis in the pelvic ultrasound image; determining a central axis of symphysis pubis in the pelvic ultrasound image; determining an axis that passes through the determined position of the inferoposterior margin of symphysis pubis and is at an angle of 135 degree with respect to the determined central axis of symphysis pubis; determining a position of a bladder neck in the pelvic ultrasound image; and calculating a distance from the determined position of the bladder neck to the determined axis to obtain a value of a bladder neck-symphyseal distance.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 16/478,094, filed on Jan. 17, 2020, which is a U.S.National Stage Application of International Patent Application No.PCT/CN2017/071277, filed on Jan. 16, 2017. The entire content of all ofthe above-identified applications is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to ultrasonic imaging devices, andparticularly to methods and systems for performing parameter measurementin an ultrasonic image.

BACKGROUND

An ultrasound imaging device is used to image the inside of a targettissue, and, based on the characteristics of some medical parameters, toperform measurements on the image obtained by the ultrasound imaging,thereby enabling the doctor to obtain the actual anatomical structureparameters of the target tissue of the patient being examined. Forexample, Pelvic Floor Ultrasound (PFU) refers to a subject that uses themedical ultrasound device to scan and image women's pelvic floor, andplays an important role in the diagnosis of gynecological urology andother pelvic floor dysfunctions. Compared with other imaging methodssuch as MRI and cystourethrography, PFU has the advantages of low cost,non-invasiveness, convenient and quick examination, etc., and hasgradually become the main method for diagnosing female pelvic floordysfunction.

There are many examination items for pelvic floor ultrasound, and thedoctors usually need to perform the measurement by drawing points in theimage for each parameter, which leads to extra work. In addition,obtaining the amount of change and relative relationship between someparameters require additional calculation, which also brings a lot ofinconvenience to the operator.

Of course, when there are multiple measurement items for the same targettissue, all of them are usually measured, one by one, by drawing points,which brings the problem of inconvenience in operation.

SUMMARY

In one embodiment, a method for measuring a parameter in an ultrasoundimage is provided, which may include:

obtaining a pelvic ultrasound image, wherein the pelvic ultrasound imageis acquired by receiving ultrasound echoes from a pelvic floor tissuewith an ultrasound probe and contains an area representing the pelvicfloor tissue;

displaying the pelvic ultrasound image;

determining a position of an inferoposterior margin of symphysis pubisin the pelvic ultrasound image;

determining a central axis of symphysis pubis in the pelvic ultrasoundimage;

determining an axis that passes through the determined position of theinferoposterior margin of symphysis pubis and is at an angle of 135degree with respect to the determined central axis of symphysis pubis;

determining a position of a bladder neck in the pelvic ultrasound image;and

calculating a distance from the determined position of the bladder neckto the determined axis to obtain a value of a bladder neck-symphysealdistance.

In one embodiment, determining the position of the inferoposteriormargin of symphysis pubis in the pelvic ultrasound image may include:

automatically identifying the position of the inferoposterior margin ofsymphysis pubis in the pelvic ultrasound image; or

detecting a click operation of a user on an area corresponding to theinferoposterior margin of symphysis pubis in the pelvic ultrasound imageto obtain the position of the inferoposterior margin of symphysis pubisin the pelvic ultrasound image.

In one embodiment, determining the central axis of symphysis pubis inthe pelvic ultrasound image may include:

automatically identifying the central axis of symphysis pubis in thepelvic ultrasound image; or

detecting a click operation of a user on an area corresponding to thecentral axis of symphysis pubis in the pelvic ultrasound image to obtainthe central axis of symphysis pubis in the pelvic ultrasound image.

In one embodiment, determining the position of the bladder neck in thepelvic ultrasound image may include:

automatically identifying the position of the bladder neck in the pelvicultrasound image; or

detecting a click operation of a user on an area corresponding to thebladder neck in the pelvic ultrasound image to obtain the position ofthe bladder neck in the pelvic ultrasound image.

In one embodiment, the method may further include:

determining a position of a proximal urethra in the pelvic ultrasoundimage; and

calculating an angle between a line connecting the determined positionof the bladder neck and the determined position of the proximal urethrain the pelvic ultrasound image and a line perpendicular to thedetermined axis to obtain a value of a urethral tilt angle.

In one embodiment, determining the position of the proximal urethra inthe pelvic ultrasound image may include:

automatically identifying the position of the proximal urethra in thepelvic ultrasound image; or

detecting a click operation of a user on an area corresponding to theproximal urethra in the pelvic ultrasound image to obtain the positionof the proximal urethra in the pelvic ultrasound image.

In one embodiment, the method may further include:

determining a position of a proximal end of posterior vesical wall inthe pelvic ultrasound image; and

calculating an angle between the line connecting the determined positionof the bladder neck and the determined position of the proximal urethraand a line connecting the determined position of the bladder neck andthe determined position of the proximal end of posterior vesical wall inthe pelvic ultrasound image to obtain a value of a posteriorurethrovesical angle.

In one embodiment, determining the position of the proximal end ofposterior vesical wall in the pelvic ultrasound image may include:

automatically identifying the position of the proximal end of posteriorvesical wall in the pelvic ultrasound image; or

detecting a click operation of a user on an area corresponding to theproximal end of posterior vesical wall in the pelvic ultrasound image toobtain the position of the proximal end of posterior vesical wall in thepelvic ultrasound image.

In one embodiment, the method may further include:

calculating an angle between the determined central axis of symphysispubis and a line connecting the determined position of theinferoposterior margin of symphysis pubis and the determined position ofthe bladder neck in the pelvic ultrasound image to obtain a value of apubourethral angle.

In one embodiment, the method may further include:

determining a position of a lowest point of posterior vesical wall inthe pelvic ultrasound image; and

calculating an angle between the determined central axis of symphysispubis and a line connecting the determined position of theinferoposterior margin of symphysis pubis and the determined position ofthe lowest point of posterior vesical wall to obtain a value of apubovesical angle.

In one embodiment, determining the position of the lowest point ofposterior vesical wall in the pelvic ultrasound image may include:

automatically identifying the position of the lowest point of posteriorvesical wall in the pelvic ultrasound image; or

detecting a click operation of a user on an area corresponding to thelowest point of posterior vesical wall in the pelvic ultrasound image toobtain the position of the lowest point of posterior vesical wall in thepelvic ultrasound image.

In one embodiment, the method may further include:

determining a position of a lowest point of posterior vesical wall inthe pelvic ultrasound image; and

calculating a distance from the determined position of the lowest pointof posterior vesical wall to the determined axis to obtain a value of apubovesical distance.

In one embodiment, the method may further include:

generating an anatomical schematic diagram of the pelvic floor tissuebased on knowledge of tissue anatomy;

displaying the anatomical schematic diagram; and

prompting the position to be determined on the anatomical schematicdiagram.

In one embodiment, the pelvic ultrasound image may be a rest framepelvic ultrasound image or a valsalva frame pelvic ultrasound image.

In one embodiment, a method for measuring a parameter in an ultrasoundimage may be provided, which may include:

obtaining a pelvic ultrasound image, wherein the pelvic ultrasound imageis acquired by receiving ultrasound echoes from a pelvic floor tissuewith an ultrasound probe and contains an area representing the pelvicfloor tissue;

displaying the pelvic ultrasound image;

determining a position of an inferoposterior margin of symphysis pubisin the pelvic ultrasound image;

determining a central axis of symphysis pubis in the pelvic ultrasoundimage;

determining an axis that passes through the determined position of theinferoposterior margin of symphysis pubis and is at an angle of 135degree with respect to the determined central axis of symphysis pubis;

determining a position of a lowest point of posterior vesical wall inthe pelvic ultrasound image; and

calculating a distance from the determined position of the lowest pointof posterior vesical wall to the determined axis to obtain a value of apubovesical distance.

In one embodiment, the method may further include:

calculating an angle between the determined central axis of symphysispubis and a line connecting the determined position of theinferoposterior margin of symphysis pubis and the determined position ofthe lowest point of posterior vesical wall in the pelvic ultrasoundimage to obtain a value of a pubovesical angle.

In one embodiment, an ultrasound imaging system may be provided, whichmay include:

a probe;

a transmitting circuit that is configured to excite the probe totransmit an ultrasonic beam to a pelvic floor tissue;

a receiving circuit that is configured to receive ultrasonic echoes ofthe ultrasonic beam through the probe to obtain ultrasonic echo signals;

a processor that is configured to: obtain a pelvic ultrasound imageaccording to the ultrasound echo signals, wherein the pelvic ultrasoundimage contains an area representing the pelvic floor tissue; determine aposition of an inferoposterior margin of symphysis pubis in the pelvicultrasound image; determine a central axis of symphysis pubis in thepelvic ultrasound image; determine an axis that passes through thedetermined position of the inferoposterior margin of symphysis pubis andis at an angle of 135 degree with respect to the determined central axisof symphysis pubis; determine a position of a bladder neck in the pelvicultrasound image; and calculate a distance from the determined positionof the bladder neck to the determined axis to obtain a value of abladder neck-symphyseal distance; and

a display that is configured to display the pelvic ultrasound image.

In one embodiment, the processor may be further configured to:

determine a position of a proximal urethra in the pelvic ultrasoundimage; and

calculate an angle between a line connecting the determined position ofthe bladder neck and the determined position of the proximal urethra inthe pelvic ultrasound image and a line perpendicular to the determinedaxis to obtain a value of a urethral tilt angle.

In one embodiment, the processor may be further configured to:

determine a position of a proximal end of posterior vesical wall in thepelvic ultrasound image; and

calculate an angle between the line connecting the determined positionof the bladder neck and the determined position of the proximal urethraand a line connecting the determined position of the bladder neck andthe determined position of the proximal end of posterior vesical wall inthe pelvic ultrasound image to obtain a value of a posteriorurethrovesical angle.

In one embodiment, the processor may be further configured to:

calculate an angle between the determined central axis of symphysispubis and a line connecting the determined position of theinferoposterior margin of symphysis pubis and the determined position ofthe bladder neck in the pelvic ultrasound image to obtain a value of apubourethral angle.

In one embodiment, the processor may be further configured to:

determine a position of a lowest point of posterior vesical wall in thepelvic ultrasound image; and

calculate an angle between the determined central axis of symphysispubis and a line connecting the determined position of theinferoposterior margin of symphysis pubis and the determined position ofthe lowest point of posterior vesical wall to obtain a value of apubovesical angle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a configuration of an ultrasoundimaging system in one embodiment;

FIG. 2 is a schematic flowchart of a method in one embodiment;

FIG. 3(a) schematically shows the placement of the probe intranslabial/transperineal ultrasound imaging, and FIG. 3(b)schematically shows the median sagittal section image obtained thereby;

FIG. 4 schematically shows the measurement of the levator hiatus in theaxial plane;

FIG. 5 schematically shows the posterior urethrovesical angle orretrovessel angle (RVA);

FIG.6(a) and 6(b) schematically shows two methods for calculating theurethral tilt angle (UTA);

FIGS. 7(a) and 7(b) schematically shows the method for measuring thepubourethral angle and the pubovesical angle;

FIG. 8 is a schematic flowchart of a pelvic measurement method in oneembodiment;

FIG. 9 is a schematic flowchart of a pelvic measurement method inanother embodiment;

FIG. 10 is an anatomical schematic diagram of a target tissue;

FIG. 11 is a schematic diagram of a reference coordinate system;

FIGS. 12 and 13 schematically show various measurement items of thepelvic floor;

FIGS. 14 and 15 are schematic flowcharts of two embodiments,respectively;

FIG. 17 shows an example of bladder contour segmentation;

FIG. 18 shows an example of RVA measurement;

FIG. 19 shows an example of UTA measurement;

FIGS. 20 and 21 show the examples of PuboVesical Angle (PVA) andPuboVesical Distance (PVD) measurements;

FIG. 22 schematically shows the detection of the lowest point ofposterior vesical wall and the calculation of PVD;

FIGS. 23 and 24 show the examples of PuboUrethral Angle (PUA) andBladder Neck-Symphyseal Distance (BSD) measurements;

FIG. 25 schematically shows the positioning of the inferoposteriormargin and the central axis of the symphysis pubis;

FIG. 26 schematically shows the method for extracting thecharacteristics of the central axis of symphysis pubis; and

FIG. 27 shows an example of the detection range of the inferoposteriormargin of the symphysis pubis.

DETAILED DESCRIPTION

The ultrasound imaging system shown in FIG. 1 may include a probe 101, atransmitting circuit 103, a transmission/reception switch 102, areceiving circuit 104, a beamformer 105, a signal processing unit 116,and an image processing unit 126. During the ultrasound imaging process,the transmitting circuit 103 may send delay-focused transmission pulseswith a certain amplitude and polarity to the probe 101 through thetransmission/reception switch 102. The probe 101 may be excited by thetransmission pulses to transmit ultrasonic waves to a target tissue (forexample, organs, tissues, blood vessels, etc. in a human or animal body,not shown in the figure). After a certain delay, the probe 101 mayreceive the ultrasonic echoes which are reflected from the target areaand carry the information of the target tissue, and convert theultrasonic echoes into electrical signals. The receiving circuit 104 mayreceive the electrical signals converted by the probe 101 to obtainultrasonic echo signals, and send the ultrasonic echo signals to thebeamformer 105. The beamformer 105 may perform processing such as focusdelay, weighting and channel summing on the ultrasonic echo signals, andthen send the ultrasonic echo signals to the signal processing unit 116where related signal processing may be performed thereon. The ultrasonicecho signals processed by the signal processing unit 116 may be sent tothe image processing unit 126. The image processing unit 126 may performdifferent processing on the signals according to different imaging modesdesired by the user to obtain ultrasound image data in different modes,and perform log compression, dynamic range adjustment and digital scanconversion, etc. on the data to obtain ultrasound images in differentmodes, such as B images, C images, D images, Doppler blood flow images,elastic images containing tissue elastic properties, etc., or othertypes of two-dimensional or three-dimensional ultrasound images. Theelastic images may be obtained by transmitting ultrasonic waves todetect the characteristics of the shear waves inside the target tissue,or by transmitting ultrasonic waves to detect the deformation of thetarget tissue due to external forces, where the shear waves may begenerated by external vibration or by excitation of ultrasonic wavestransmitted into the target tissue.

In some embodiments of the present disclosure, the signal processingunit 116 and the image processing unit 126 may be integrated on a mainboard 106. Alternatively, one or two or more units of them may beintegrated in one processor/controller chip.

The ultrasound imaging system may further include an input/output port108, which may be disposed on the main board 106. The ultrasound imagingsystem may be connected to an input/output device through theinput/output port 108, and may receive, through the input/output port108, an instruction signal inputted through the input/output device. Theinstruction signal may include a control instruction for controlling thetiming of the transmitting and receiving of the ultrasonic waves, anoperation input instruction for editing or annotating, etc. theultrasound images, an output instruction for reminding the user, orother types of instructions. Generally, the operation instructionobtained when a user edits, annotates, or performs other operation onthe ultrasound image may be used for measurement of the target tissue.The input/output device may include one of, or a combination of more of,a keyboard, a mouse, a scroll wheel, a trackball, and a mobile inputdevice (a mobile device with a touch display, a mobile phone, etc.),etc. The corresponding input/output port 108 may be a wirelesscommunication device, a wired communication device, or a combinationthereof. The input/output port 108 may also be implemented based onUniversal Serial Bus (USB), a bus protocol such as Controller AreaNetwork (CAN), and/or a wired network protocol, etc.

In addition, the ultrasound imaging system may further include a display107 which may display the ultrasound image data from the imageprocessing unit. The display 107 may be a touch screen display. Theultrasound imaging system may also be connected to another displaythrough the input/output port to implement a dual-display system. Inaddition, the display in this embodiment may include one or multipledisplays. The number of displays will not be limited in this embodiment.The displayed ultrasound image data (ultrasonic image) may be displayedon one display or on multiple displays simultaneously, and it is alsopossible that the parts of the ultrasound image are respectivelysynchronously displayed on multiple displays, which will not be limitedin this embodiment.

As shown in FIG. 2, a flowchart of a method for measuring parameters inan ultrasound image is provided. The process of performing the parametermeasurement method in this embodiment will be described in detail belowwith reference to FIG. 1.

In step S210, the image processing unit 126 in the ultrasound imagingsystem may acquire an ultrasound image which contains the target tissue.As shown in FIG. 1, the ultrasound image may be obtained by receivingthe ultrasound signals from the target tissue with the ultrasound probe101. The ultrasound signals in this embodiment will not be limited tothe ultrasound echo signals mentioned above with reference to FIG. 1,but may also be ultrasound signals generated in the target tissue by,for example, a photoacoustic imaging method. In addition, the targettissue here may include, but not limited to, pelvic floor tissue. Thepelvic floor tissue may include one or more anatomical tissue structuresin a female pelvic cavity, such as uterus, labia, perineum, pelvis,symphysis pubis, etc. The ultrasound image containing the pelvic floortissues may include, but not limited to, anterior pelvic ultrasoundimages and posterior pelvic ultrasound images, and may also includemiddle pelvic ultrasound images. The commonly used measurement items ofpelvic floor ultrasound may be divided into three parts: anterior pelviccavity measurement items, middle pelvic cavity measurement items andposterior pelvic cavity measurement items. The parameter measurementbased on the anterior pelvic ultrasound image and the middle pelvicultrasound image may be mainly performed on the median sagittal sectionimage obtained using a translabial probe or a transperineal probe (asshown in FIG. 3(a) and FIG. 3(b), where FIG. 3(a) shows the placement ofthe translabial/transperineal ultrasound probe and FIG. 3(b) shows themedian sagittal section image obtained thereby). The parametermeasurement based on the posterior pelvic ultrasound image may beperformed on the ultrasound image acquired using an intracavity probe(endoanal probe) or on a proper section image selected in the axis planein a static 3D ultrasound image or a 4D ultrasound image acquired usinga transperineal or transvaginal probe. Regarding the parametermeasurement based on the posterior pelvic ultrasound image, thedescription of this embodiment will be based on the second casedescribed above, that is, the example where the posterior pelvicultrasound image is acquired using the transperineal or transvaginalprobe will be described.

In step S220, the image processing unit 126 in the ultrasound imagingsystem may output the ultrasound image to the display where theultrasound image will be displayed. See the description regarding thedisplay 107 above. In this embodiment, the manner of displaying theultrasound image will not be limited. For example, the ultrasound imagemay be displayed on multiple displays at the same time, or only on onedisplay. Alternatively, the parts of the ultrasound image may berespectively displayed on multiple displays synchronously, therebyexpanding the viewing angle of the ultrasound image. Furthermore, in oneembodiment, the image processing unit 126 may transmit the ultrasoundimage to the display through a wireless or wired manner. The display maybe a touch display on a mobile device. Furthermore, in one embodiment,the ultrasound image may be displayed on a first layer, where the firstlayer may be a software interface layer other than the layer fordisplaying the non-image data such as annotations, markers, text andcursors, etc. Correspondingly, the software interface layer fordisplaying the non-image data such as annotations, markers, text andcursors, etc. may be referred to as a second layer. The areas of thesecond layer which overlap the first layer may be set as beingtransparent so as to not block the ultrasound image and enhance thevisibility and user-friendliness. Furthermore, the entire second layermay be set as being transparent.

In step S230, the image processing unit may obtain a measurementinstruction based on the ultrasound image. In step S240, the imageprocessing unit may calculate a parameter related to the target tissueaccording to the measurement instruction to obtain a calculation result.

In this embodiment, the measurement instruction may be automaticallydetermined by the system based on the ultrasound image. Alternatively,the measurement instruction may be obtained based on a measurementoperation of a user on the ultrasound image, or an input inputted by auser on the ultrasound image according to a system prompt.

The purpose of the measurement instruction is to calculate the parameterrelated to the target tissue. The medical meaning of some parameterswill be described in detail below.

In academic and clinic, there are many parameters related to theanterior pelvic ultrasound image, most of which are related to thediagnosis of Pelvic Organ Prolapsed (POP) and Urinary Incontinence. Inthe present embodiment, the parameters that may be involved may include,but not limited to, the following.

1) Posterior Urethro Vesical Angle or RetroVesical Angle (RVA), as theangle shown in FIG. 5 with the white thick solid line in the image. TheRVA is the angle between the proximal urethra and the rear end of thebladder triangle;

2) Urethral Tilt Angle (UTA) or Urethral Inclination (UI). FIG. 6(a) andFIG. 6(b) show two methods for calculating the UTA, where FIG. 6(b)shows the calculation method of Maglinte et al. The angles obtained bythe two methods are mutually complementary. When the UTA is finally usedto calculate the urethral rotation angle (URA), the two calculationmethods are equivalent;

3) PuboUrethral Angle (PUA). FIG. 7(a) shows the pubourethral angle PUA,which is the angle between the central axis of the symphysis pubis andthe line connecting the inferoposterior margin of the symphysis pubisand the bladder neck;

4) Bladder Neck-Symphyseal Distance (BSD) or PuboUrethral Distance(PUD);

5) PuboVesical Angle (PVA). FIG. 7(b) shows the pubo vesical angle(PVA), which is the angle between the central axis of the symphysispubis and the line connecting the inferoposterior margin of thesymphysis pubis and the lowest point of the posterior wall of thebladder;

6) PuboVesical Distance (PVD) or Bladder Descent Max (BL Desc. Max);

7) Urethral Rotation Angle (URA);

8) Bladder Neck Descend or bladder neck mobility (BND); and

9) Bladder wall descend (BWD); etc.

A large part of these parameters depend on how to establish anappropriate reference coordinate system. For example, both BSD and PVDneed a reference to the position of the symphysis pubis and its centralaxis, which depends on the establishment of a reference coordinatesystem with the central axis of the symphysis pubis being the X axis.

At the same time, there is relevance between these parameters. See FIG.3(b) and the term explanations in the table below.

Abbre- English Name viation Definition Bladder neck BN Also be referredto as urethrovesical junction (UVJ), i.e. the junction of bladder andurethra Bladder neck BND The descending distance of the descend bladderneck in rest state and maximum valsalva state Urethrovesical UVJ I.e. BNjunction Symphysis SP, PS From literatures and IUAG/ICS pubis, Pubisrecommendations, the abbreviation symphysis SP is more commonly usedInferoposterior Lower boarder of symphysis margin of the symphysis pubisInternal urethral I.e. BN or UVJ orifice Proximal urethra The part ofthe urethra near the bladder. The end away from the bladder is referredto as distal urethra Pelvic Floor PFD A collective name for variousDysfunction symptoms of the pelvic floor Pelvic organ POP Generallyreferring to pelvic floor prolapsed, organs (such as the bladder, etc.)bulging from the vagina Levator Ani muscle LA Pelvic Floor Muscle PFMCWhen performing a 3D levator ani Contraction muscle imaging, the patientis usually required to perform an anal contraction action Uterus UTBladder B Urethra U Vagina V Perineum P Ampullae Recti R Anal RectumAngle ARA Anal Canal AC Pubourethral Angle PUA Also referred to as gammaangle Bladder Neck- BSD The distance from UVJ (or BN) to Symphyseal theX axis of the coordinate system Distance (according to another way, BSDis defined as the distance from the UVJ to the origin of the coordinatesystem) Posterior PUV, Also referred to as retrovesical angleUrethroVesical PUVA, (RVA) or Beta angle Angle, RVA PuboVesical anglePVA The angle between the central axis of the symphysis pubis and theline connecting the inferoposterior margin of the symphysis pubis andthe lowest point of the posterior wall of the bladder PuboVesical PVDThe distance from the lowest point of Distance BL Desc. the posteriorwall of the bladder to Or Bladder Max the X axis of the coordinatesystem Descent Max Urethral Tilt Angle UTA The angle between the(proximal) urethra and the central axis of the human body, or thecomplementary angle thereof Urethral angle UA The urethral angle isdefined as the angle between the distal urethra and the proximalurethra. Different from UTA and UR, UA represents the degree ofcurvature of the urethra itself Urethral rotation URA The magnitude ofthe change of Angle UTA Natural image A Cartesian coordinate systemwhere coordinate system the image center is the origin, the image widthincreasing direction is the positive direction of X axis and the imageheight increasing direction is the negative direction of Y axis

Regarding the measurement of dynamic change, the user may perform themeasurement on a second static frame after completing the measurement ona static frame. At this time, the system may display the measurementresult of the second frame in real time, and at the same time calculatethe change of certain measurement value relative to the first frame,such as:

1) the relative change of BSD, i.e. the descending distance of thebladder neck BND,

2) the relative change of PVD, i.e. the descending distance of theposterior wall of the bladder BWD, and

3) the relative change of UI, which corresponds to the urethral rotationangle UR.

When the measurement on the second frame is completed, if the user editsthe input of the first frame, the dynamic change as shown above willalso be updated and displayed in real time.

For example, URA, BND and BWD may be obtained through dynamic changes ofUTA, BSD and PVD respectively; PUA and BSD, and PVA and PVD, depend onthe same input information respectively; UTA/UR and PUA/BSD all dependon the determination of UVJ points. When the current ultrasoundequipment is applied to the measurement of the pelvic floor, theexistence of the above relevance is not taken into account, but they areusually summarized by the ultrasound doctor after measuring each itemseparately, which will definitely increase the burden on the doctor.Furthermore, because there is common information between the parameters,separate measurement of parameter will inevitably lead to measurementinconsistent and errors. For example, UTA, PUA, and BSD share the UVJpoint. When measuring separately, the operator needs to select the UVJpoint three times. The difference between these three selections willbring inconsistent measurement results.

The parameters based on the posterior pelvic ultrasound image may bemainly used to evaluate the pelvic organ prolapsed and fecalincontinence. The common parameters are related to the levator animuscle group, such as: (see FIG. 4)

a) Levator Hiatus area (LH Area), 41 in FIG. 4,

b) Levator Hiatus Circumference (LHCirc), 42 in FIG. 4,

c) the length of the Levator Hiatus anteroposterior diameter (LH AP, 44in FIG. 4) and the Levator Hiatus Lateral Diameter (LH Lateral Diam, 43in FIG. 4) of the levator hiatus, and

d) Levator urethra gap (left and right) (LUG, 45 in FIG. 4), etc.

The parameters a to d mentioned above may be mainly related to the traceof the levator hiatus and the selection of the urethra. Ultrasounddoctors usually use a trackball to perform curve tracing along thedirection of the levator anus muscle, which is time-consuming and easyto mis-operate. In addition, there are large differences betweendifferent operators and between different measurements of the sameoperator. These differences will undoubtedly affect the assessment ofthe degree of pelvic floor muscle tears, and may even cause misseddiagnosis or misdiagnosis.

In order to reduce the burden on the doctors, improving the measurementefficiency and reducing the measurement errors are desired. In oneembodiment, a new pelvic measurement method is proposed. In this method,the use of the relevance between parameters and the repetitiveness ofinput information are maximized. The positions of the measurement pointsmay be inputted one by one in a programmable order, and the availablemeasurement results may be updated and displayed in real time as theinput information increases. This solution also well supports theautomatic comprehensive summary of the results of two measurements,eliminating the inconvenience and possible errors caused by theoperator's own calculations. In the following, the measurement based onthe anterior pelvic ultrasound image will be described in detail.

The measurements based on the anterior pelvic ultrasound images may beperformed on a two-dimensional median sagittal section image. Themeasurement process of the anterior pelvic cavity is complicated, whichinvolves many parameters and usually needs to compare the measurementresults of two frames. The first frame may be obtained by acquiring amedian sagittal section image of the human body with a transperineal ortransvaginal probe when the person being examined is in a relaxed state,which may also be referred to as a rest frame. The second frame may beobtained under the condition that the pelvic cavity of the person beingexamined is exerted downward to the maximum extent, which may also bereferred to as valsalva frame and may be used to calculate the mobilityof the pelvic floor organs such as the bladder and the urethra relativeto the rest frame. The rest frame may be used as a reference image tocalculate the amount of change of the valsalva frame relative to therest frame.

Different from the traditional scattered measurement solutions, the newpelvic measurement solutions proposed in this embodiment is moreintegrated. As shown in FIG. 8, to accomplish step 5230 of FIG. 2 (theimage processing unit obtains the measurement instruction based on theultrasound image), the following process may be used.

In step 91, the input/output device (such as a keyboard, a mouse, atrackball, a touch screen or other human-computer interaction devices)may be used to receive at least one measurement item inputted by theuser, and each measurement item may correspond to the position of atleast one anatomical feature. Regarding the measurement items in thisembodiment, reference may be made to the description above. Onemeasurement item may correspond to a parameter of the target tissue, andone parameter may be calculated based on at least two anatomicalfeatures. The anatomical features herein may refer to the specificanatomical features associated with the parameter when the parameter ofthe target tissue is medically defined, such as the proximal urethra andthe rear end of the bladder triangle associated with the posteriorurethra vesical angle or retro vesical angle, the proximal urethra andthe central axis of human body associated with the urethral tilt angle,the central axis of the symphysis pubis, the inferoposterior margin ofthe symphysis pubis and the bladder neck associated with thepubourethral angle, the urethrovesical junction associated with thebladder neck descend, the central axis of the symphysis pubis, theinferoposterior margin of the symphysis pubis and the lowest point ofthe posterior wall of the bladder associated with the pubovesical angle,and the urethrovesical junction, etc. Reference may be made to thedescription above, and the anatomical features listed here are not inexhaustion. The anatomical feature may be an anatomical feature actuallyexisting in the target tissue. Alternatively, the anatomical feature maybe an anatomical reference line or reference position that isartificially defined in order to achieve the measurement of the targettissue. Image positions corresponding to the anatomical features may beidentified on the ultrasound image. The image position may be a pixel,or a block or line area composed of multiple pixels. Alternatively, theimage position may a neighborhood of a certain pixel.

In step 92, according to the inputted measurement item, at least oneanatomical feature item associated with the measurement item may beobtained to form a feature set to obtain the measurement instruction. Inone embodiment, the feature set may be a group of anatomical featureitems. The elements in the group may have three characteristics: 1.certainty (the elements in the group are certain); 2. mutualdissimilarity (the elements in the group are different from each other);3. disorder (the elements in the group have no order). The feature setmay be automatically obtained by the system based on the inputtedmeasurement item.

In step 93, the position of each anatomical feature item in the featureset may be determined according to the feature set, thereby obtainingthe measurement instruction. In the step of determining the position ofeach anatomical feature item in the feature set, the position of eachanatomical feature item in the feature set may be determined by the userclicking on the ultrasound image, thereby obtaining the measurementinstruction; alternatively, the position of each anatomical feature itemin the feature set may be automatically identified by the system,thereby obtaining the measurement instruction. When the position of eachanatomical feature item is determined, a corresponding coordinateposition in the measurement coordinate system may be accordinglydetermined. Therefore, the measurement instruction herein may includethe information for determining the coordinate position of one or moreanatomical feature items in the feature set.

In step 94, the determination of the anatomical feature items in thefeature set may be completed.

In step 97, the measurement results may be summarized.

In one embodiment, a step 95 may be further included, in which ananatomical schematic diagram may be displayed for prompting the featureset. Alternatively, a text may be used to prompt the feature set. Boththe anatomical schematic diagram and the text can be used to prompt theuser to click on the ultrasound image to determine the position of eachanatomical feature.

In one embodiment, a step 96 may be further included, in which anavailable measurement value may be displayed, i.e., the calculationresult of the parameter obtained according to the measurementinstruction may be displayed. The method for displaying the measurementvalue will be described in detail below.

Referring to FIG. 9, in one embodiment, in step S230 (the imageprocessing unit obtains the measurement instruction based on theultrasound image), the following process may also be used.

In step 12, the input/output device (such as a keyboard, a mouse, atrackball, a touch screen or other human-computer interaction devices)may be used to receive at least one measurement item inputted by theuser, and each measurement item may be related to at least oneanatomical feature. This step may be the same as step 91 above.

In step 14, according to the inputted measurement item, at least oneanatomical feature associated with the measurement item may be obtainedto form a feature set, the determination order of the at least oneanatomical feature when measuring the parameter may be determinedaccording to the feature set, and the measurement sequence may bedetermined according to the feature set and the determination order. Inone embodiment, the feature set may be a group of anatomical features.The measurement sequence may be automatically implemented by the system.

In step 16, the position of each anatomical feature in the feature setmay be sequentially determined according to the feature set, therebyobtaining the measurement instruction. In the step of determining theposition of each anatomical feature in the feature set, the position ofeach anatomical feature in the feature set may be determined by the usersequentially clicking on the ultrasound image according to themeasurement sequence, thereby obtaining the measurement instruction;alternatively, the position of each anatomical feature in themeasurement sequence may be automatically identified by the system,thereby obtaining the measurement instruction. When the position of eachanatomical feature is determined, a corresponding coordinate position inthe measurement coordinate system may be accordingly determined.Therefore, the measurement instruction herein may include theinformation for determining the coordinate position of one or moreanatomical features in the feature set.

In step 18, the determination of the anatomical features in themeasurement sequence may be completed.

In step 17, the measurement results may be summarized.

In one embodiment, a step 13 may be further included, in which ananatomical schematic diagram may be displayed for prompting the featuresets. Alternatively, a text may be used to prompt the feature set. Boththe anatomical schematic diagram and the text can be used to prompt theuser to click on the ultrasound image to determine the position of eachanatomical feature.

In one embodiment, a step 15 may be further included, in which anavailable measurement value may be displayed, i.e., the calculationresult of the parameter obtained according to the measurementinstruction may be displayed. The method for displaying the measurementvalue will be described in detail below.

In the embodiments above, whether determining the position of eachanatomical feature in the feature set according to the feature set toobtain the measurement instruction or sequentially determining theposition of each anatomical feature in the feature set according to themeasurement sequence, one of the following methods may be used todetermine the position of each anatomical feature in the feature set toobtain the measurement instruction.

In the first method, the user's determination operation to one or moreanatomical features in the feature set on the ultrasound imagesequentially through the input/output device (which may include akeyboard, a mouse, a trackball, or a touch screen) may be received, andthe measurement instruction may be obtained according to thedetermination operation inputted by the user. The order of thedetermination operation of the user may be an orderly operationperformed according to the measurement sequence above. The orderlyoperation may be performed according to the determination order in themeasurement sequence.

In the second method, the user's determination operation to one or moreanatomical features in the feature set on the ultrasound imagesequentially through the input/output device may be received, and themeasurement instruction may be obtained according to the determinationoperations inputted by the user. The determination operations may bedetermination operations in any order. Here, determination operations inany order may also be understood as the determination operations thatare completed without a determination order of the anatomical featuresgiven by the system or the manual.

The determination operation above may be used to determine the positionof each anatomical feature in the ultrasound image.

In one embodiment, the feature set obtained in FIG. 8 or the positionsequence obtained in FIG. 9 may be prompted. The feature set ormeasurement sequences may be prompted in the following ways.

First, based on the knowledge of tissue anatomy, an anatomical schematicdiagram of the target tissue may be generated, as shown in FIG. 10.

Then, the anatomical schematic diagram may be displayed on the display.The anatomical schematic diagram may be displayed outside the area ofthe ultrasound image or on the ultrasound image. In one embodiment, theanatomical schematic diagram may be shown on the second layer mentionedabove.

Thereafter, on the anatomical schematic diagram, the concentratedanatomical features may be marked (as shown in the left view in FIG. 10,in which the black dots indicate the anatomical features), or themeasurement sequence above may be marked (as shown in the right view inFIG. 10). In the present embodiment, marking the measurement sequencemay include marking the concentrated anatomical features in the featureset on the anatomical schematic diagram and marking the determinationorder of the determination operations of the anatomical features in thefeature set (for example, the number in the right view in FIG. 10 mayindicate the corresponding determination order of the anatomicalfeatures represented by the black dot). In addition to marking thedetermination order with the numbers in FIG. 10, it may also be possiblethat the anatomical feature currently to be determined is displayed byscrolling on the screen for prompting. In one embodiment, the method forthe scrolling display may include sequentially displaying the anatomicalfeature currently to be determined in the feature set in any order or inthe determination order.

Further, determining the position of each anatomical feature in thefeature set to obtain the measurement instruction may further includes:determining a determination order corresponding to multiple anatomicalfeatures when measuring the parameter according to the measurementsequence, and prompting the multiple anatomical features to the user byscrolling text.

Because the pelvic floor examination may desire to compare the mobilityof the organs in two acquired images, it is desired to find a fixedpoint in the two measurements to establish an appropriate referencecoordinate system before the measurement. In one embodiment, the methodfor measuring the parameters in the ultrasound image may further includethe following steps.

First, a reference coordinate system may be determined. The referencecoordinate system may be at least one of a first Cartesian coordinatesystem with the inferoposterior margin of the symphysis pubis being theorigin and the central axis of the symphysis pubis being the 45 degreeangle of the second quadrant, a second Cartesian coordinate system withthe inferoposterior margin of the symphysis pubis being the origin andthe central axis of the symphysis pubis being the X axis and a thirdCartesian coordinate system with the horizontal direction being the Xaxis and the vertical direction being the Y axis;

Then, in step S240, based on the determined reference coordinate system,the parameter may be calculated according to the measurementinstruction.

This embodiment may be compatible with at least three referencecoordinate systems. As shown in FIG. 11, A is a Cartesian coordinatesystem with the inferoposterior margin of the symphysis pubis being theorigin and the central axis of the symphysis pubis being the 45-degreeangle of the second quadrant, B is a Cartesian coordinate system withthe inferoposterior margin of the symphysis pubis being the origin andthe central axis of the symphysis pubis being the x axis, and C is aCartesian coordinate system with the horizontal direction being thex-axis and the vertical direction being the y-axis.

BSD/PVD may be calculated in different methods selected from the methodsbelow for two different coordinate systems.

1) Measuring the distance from a point to the X axis of the coordinatesystem, or

2) Measuring the distance from a point to the Y axis of the coordinatesystem, or

3) Measuring the distance from a point to the origin of the coordinatesystem.

Note: reference may be made to FIG. 12 which shows the first calculationmethod.

The user may select one of these three coordinate systems in the systempreset options. For example, in one embodiment, the reference coordinatesystem may be determined in one of the following methods.

In the first method, the inferoposterior margin of the symphysis pubisand the central axis of the symphysis pubis inputted by the user on theultrasound image may be received, and the first Cartesian coordinatesystem, the second Cartesian coordinate system or the third Cartesiancoordinate system may be established according to the user input.

In the second method, the inferoposterior margin of the symphysis pubisand the central axis of the symphysis pubis may be automaticallydetected in the ultrasound image based on pattern recognition, and thefirst Cartesian coordinate system, the second Cartesian coordinatesystem or the third Cartesian coordinate system may be establishedthereby.

Alternatively, the following method may also be used. First, the optionsof at least three reference coordinate systems may be presented, and thereference coordinate systems may be selected from the first Cartesiancoordinate system, the second Cartesian coordinate system and the thirdCartesian coordinate system according to customer requirements;thereafter, a selection instruction for selecting the referencecoordinate system inputted by the user may be received, and thereference coordinate system may be determined according to the selectioninstruction. The first Cartesian coordinate system, the secondcoordinate system, and the third Cartesian coordinate system may beobtained using the first method or second method described above.

When establishing a coordinate system based on the first method, whetherbeing a 45-degree angle in the second quadrant or directly being the Xaxis of the coordinate system, the inferoposterior margin of thesymphysis pubis and the central axis of the symphysis pubis are relatedto the establishment of the coordinate system. Therefore, the user mayneed to input the inferoposterior margin of the symphysis pubis and thecentral axis of the symphysis pubis. In this embodiment, two manualinput solutions may be provided to receive the inferoposterior margin ofthe symphysis pubis and the central axis of the symphysis pubis inputtedby the user on the ultrasound image.

1) The user may first input the position information 181 of theinferoposterior margin of the symphysis pubis 182, as shown in the leftview in FIG. 16. Then, as shown in the right view in FIG. 16, the usermay operate an input device (such as a trackball) to determine theposition 183 of the central axis. For example, in one embodiment, aclick input may be received to determine the inferoposterior margin ofthe symphysis pubis. When the trackball or mouse or the touch contactwith the display screen moves, the candidate center axis may movetherewith. When it is detected that the movement stopped, the candidatecentral axis may be displayed at the position where the movement stoppedso as to determine the input of the central axis of the symphysis pubis.It should be noted that the position of the central axis may not have tobe related to the absolute position of the cursor, and the system doesnot even need to display the mouse cursor. When the input device such asthe mouse or the trackball moves, the candidate center axis may moveaccordingly until the operator notifies the system by operation such asclicking, etc. that the selection of the center axis position iscompleted.

2) The user may also directly input the positions of the two points todetermine the position of the central axis of the symphysis pubis.

When establishing a coordinate system based on the second method, thetwo inputted points may also be automatically identified by the system.In this embodiment, a method for automatically determining a coordinatesystem is proposed, in which a mode recognition method may be used toautomatically detect the inferoposterior margin of the symphysis pubisand the central axis of the symphysis pubis, thereby determining theposition of the coordinate system. The following will describe how todetect these two anatomical positions.

In the automatic detection of the inferoposterior margin of thesymphysis pubis, pattern recognition may be used to detect theinferoposterior margin of the symphysis pubis. In one embodiment, apositive image sample containing the inferoposterior margin of thesymphysis pubis and a negative image sample not containing theinferoposterior margin of the symphysis pubis may be inputted to adetector for training; a recognition model may be obtained based on thetraining; and the inferoposterior margin of the symphysis pubis may beautomatically detected in the ultrasound image using the recognitionmodel. For example, first, the image patches of the inferoposteriormargin of the symphysis pubis may be collected from a number of imagesthat have been subjected a preprocessing such as smoothing or denoising,and be performed thereon certain normalization processing, which will beused as positive samples. The images that do not contain theinferoposterior margin of the symphysis pubis may be collected asbackground images. The image patch of any size in any position in thesebackground images may be used as a negative sample. A specific detectormay be trained using these positive samples and background images todetect the inferoposterior margin of the symphysis pubis. For example,the specific detector may include, but not limited to, the followingdetectors:

1) Cascade adaBoost detector using Haar features

2) Cascade adaBoost detector using Local Binary Patterns (LBP) features

3) Support Vector Machine (Latent SVM) detector

4) Detector based on neural network

In this embodiment, the type of the detector will not be limited, but beused as a part of an automatic measurement framework. Depending on thedetector, the training method will be different. Regarding thedetection, this method may use a search method based on a moving window(as shown in FIG. 27). In order to improve the detection efficiency, thearea for detecting the symphysis pubis may be concentrated in certainpossible area (for example, in the area of 0.1 w to 0.5 w, 0.1 h to 0.9h). The window-type search may be performed in certain step length inpixels at different scales, and the most likely area may be selectedtherefrom. The search may be performed from left to right and top tobottom, and the most likely area may be selected therefrom. Thesymphysis pubis areas may be selected from a large number of imagescontaining the symphysis pubis as the positive samples for training thedetector. When the image is flipped or mirrored, the area for detectionmay be adjusted accordingly.

In the automatic detection of the central axis of the symphysis pubis,the starting point of the central axis of the symphysis pubis isdetermined as the inferoposterior margin of the symphysis pubis isdetermined. The rest is detecting the direction of the central axis ofthe symphysis pubis. In one embodiment, the process of automaticallydetecting the inferoposterior margin of the symphysis pubis and thecentral axis of the symphysis pubis in the ultrasound image based onpattern recognition may include the following steps.

First, the starting point of the central axis of the symphysis pubis maybe determined according to the inferoposterior margin of the symphysispubis. A candidate ray representing the central axis of the symphysispubis may be determined from the starting point. The candidate ray hasinitial deflection angle. Multiple candidate rays may be obtained in apredetermined range centered on the initial deflection angle and inpredetermined intervals. For example, in a natural image Cartesiancoordinate system, the search may be performed in a search rangecentered on a certain common angle of the symphysis pubis (such as 135degree) in a certain interval of angle to obtain the most probabledirection as the direction of the central axis of the symphysis pubis.As shown in FIG. 25. When the image is flipped or mirrored, the searchrang may be adjusted accordingly. In FIG. 25, the ray sc may representthe initial deflection angle of the central axis of the symphysis pubis,and the dotted lines may represent multiple candidate rays. As shown inFIG. 25, the point S may be obtained by a detector (such as a cascadedadaboost classifier). The ray SC may be obtained by searching in aspecific range (for example, in the natural image Cartesian coordinatesystem, the search may be performed in a range which is centered on135-degree and formed by respectively deflecting 30 degree to the leftand to the right, and in an interval of 1 degree, to obtain the mostprobable angle). After the ray SC is determined, the X axis may beobtained by rotating the SC ray clockwise 135 degrees around the S point(coordinate system C1) or directly using the ray SC as the X axis(coordinate system C).

Second, the pixel characteristics of the multiple candidate rays may beextracted, and one of the multiple candidate rays may be determined asthe central axis of the symphysis pubis based on the pixelcharacteristics. For example, for each candidate ray, characteristicsrelated to said candidate ray may be extracted, such as selecting thepixel values on the normal lines at both sides of the candidate ray atcertain intervals along the candidate ray as the characteristics, asshown in FIG. 26. The extracted characteristics may be inputted to apre-trained detector and scored to obtain a group of scores(corresponding to a group of candidate rays). The candidate ray with thehighest score may be determined as the central axis of the symphysispubis.

There are a variety of detectors that can be used to detect the centralaxis of the symphysis pubis, such as a likelihood detector based on aGaussian distribution or a detector based on (linear, polynomial,logistic, etc.) regression models, etc. The input of these detectors maybe the characteristics equivalent to the characteristics inputted duringthe training phase, and the output may be continuous real number whichrepresents the score to the input.

After the reference coordinate system is determined, the user may definethe measurement items included in the measurement requirements (such asBSD, UTA, etc.) in advance, and the ultrasound imaging system maydetermine the anatomical feature to be inputted according to thesemeasurement requirements, and automatically arrange the input order. Theultrasound imaging system may further display an anatomical schematicdiagram on the screen to prompt the user how to perform a semi-automaticmeasurement operation according to the anatomical features automaticallydetermined by the system. During the user determining the positions ofthe anatomical features according to the anatomical schematic diagram,the system may display the currently available measurement results inreal time. It can be seen that, unlike the traditional separatemeasurement methods, the present embodiment proposes an integratedintelligent manual measurement method (see FIGS. 8 and FIG. 9). Based onthe process described in FIG. 9, the following illustrates how toperform the intelligent manual measurement.

In one embodiment, in step 12 in FIG. 9, the user may define thefollowing measurement items through a preset menu:

(1) the angle PUA between the symphysis pubis and UVJ,

(2) the distance BSD from UVJ to X axis

(3) the urethral tilt angle UTA,

(4) the retrovesical angle RVA,

(5) the pubovesical angle PVA, and

(6) the distance PVD from the lowest point of the posterior wall of thebladder to the X axis.

In step 14, the ultrasound imaging system may automatically calculatethe pelvic floor anatomical feature information needed to be inputtedaccording to the logical relationship between these measurement items,i.e., determine the feature set of the anatomical features and generatea default measurement sequence, as follows. See FIG. 14.

(a) the lower boarder of SP,

(b) the central axis of SP,

(c) the urethrovesical junction (UVJ),

(d) the proximal urethra,

(e) the proximal end of posterior vesical wall, and

(f) the lowest point of posterior vesical wall.

The anatomical structures of the above input items are schematicallyshown in FIG. 12 and FIG. 13. FIG. 12 schematically shows themeasurement items of the pelvic floor, including the pubourethral anglePUA, the posterior urethrovesical angle RVA, the urethral tilt angleUTA, and the distance BSD from the symphysis pubis to the x axis.

FIG. 13 schematically shows the measurement items of the pelvic floor,including the pubovesical angle PVA, the posterior urethrovesical angleRVA, the urethral tilt angle UTA, and the distance PVD from thesymphysis pubis to the x axis. The items a) and b) may be used todetermine the coordinate system. At this time, the user can sort theseinputs according to personal habits, or choose not to change them. Whena new qualified image is acquired, the user may input the aboveinformation through an input device in a predefined order (as shown inFIG. 14). As user input increases, the system will gradually update themeasurement results until the measurement is completed.

As the inputted information increases, the measurement results will alsobe increased accordingly. The input order of the information items a tof may be preset, and may also be deleted as needed. The definitions of ato f and 1 to 6 are shown above. As shown in FIG. 14, after the positionof (c) the urethrovesical junction is determined, the parameters (1) theangle PUA between the symphysis pubis and UVJ and (2) the distance BSDfrom UVJ to the X axis may be displayed; after the position of (d) theproximal end of the urethra is determined, the parameter (3) theurethral tilt angle UTA may be displayed; after the position of (e) theproximal end of posterior vesical wall is determined, the parameter (4)the retrovesical angle RVA may be displayed; and after the position of(f) the lowest point of posterior vesical wall is determined, theparameters (5) the pubovesical angle PVA and (6) the distance PVD fromthe lowest point of the posterior wall of the bladder to the X axis maybe displayed.

Based on the above embodiment, the user may choose not to measure theangle PVA and the distance PVD. In this case, the measurementrequirements will be simplified as follows:

(1) the angle PUA between the symphysis pubis and UVJ,

(2) the distance BSD from UVJ to X axis,

(3) the urethral tilt angle UTA, and

(4) the retrovesical angle RVA.

In this case, the information of the pelvic floor anatomical featuresthat needs to be inputted in the feature set will also be changed, and adefault measurement sequence may be generated, as follows. See FIG. 15.

(a) the lower boarder of SP,

(b) the central axis of SP,

(c) the urethrovesical junction (UVJ),

(d) the proximal end of urethra, and

(e) the proximal end of posterior vesical wall.

The entire simplified measurement process is shown in FIG. 15. After theposition of (c) the urethrovesical junction is determined, theparameters (1) the angle PUA between the symphysis pubis and UVJ and (2)the distance BSD from UVJ to the X axis may be displayed; after theposition of (d) the proximal end of the urethra is determined, theparameter (3) the urethral tilt angle UTA may be displayed; and afterthe position of (e) the proximal end of posterior vesical wall isdetermined, the parameter (4) the retrovesical angle RVA may bedisplayed.

In order to further simplify the operation process of the manualmeasurement or reduce the calculation of the automatic measurement, inone embodiment, the feature set may include at least the inferoposteriormargin of the symphysis pubis and the central axis of the symphysispubis. Furthermore, the first two anatomical features in the measurementsequence may be the inferoposterior margin of the symphysis pubis andthe central axis of the symphysis pubis, so that the process ofobtaining the reference coordinate system may be added to themeasurement operation flow, thereby simplifying the flow operation. Whenthe system performs the automatic identification and calculation basedon the feature set and/or the measurement sequence, the system may firstdetermine the relevant position of the reference coordinate systemaccording to the feature set and/or measurement sequence, and thenperform the calculation of specific parameters. Specifically, in oneembodiment, the process of calculating the parameters related to thetarget tissue according to the measurement instruction to obtain thecalculation result may include the following steps.

First, the image processing unit may determine the reference coordinatesystem based on the positions of the first two anatomical structures inthe measurement sequence. The first two anatomical structures may beinferoposterior margin of the symphysis pubis and the central axis ofthe symphysis pubis.

Thereafter, according to the positions of the remaining anatomicalfeatures in the measurement sequence, and based on the determinedreference coordinate system, the parameter to be measured may becalculated to obtain the corresponding calculation result.

The image processing unit may use one of the following two methods todetermine the reference coordinate system according to the positions ofthe first two anatomical features in the measurement sequence.

In the first method, the inferoposterior margin of the symphysis pubisand the central axis of the symphysis pubis inputted by the user on theultrasound image may be received, and a first Cartesian coordinatesystem, a second Cartesian coordinate system or a third coordinatesystem may be established according to the user input.

In the second method, the inferoposterior margin of the symphysis pubisand the central axis of the symphysis pubis may be automaticallydetected in the ultrasound image based on pattern recognition, and afirst Cartesian coordinate system, a second Cartesian coordinate systemor a third coordinate system may be established thereby. Regarding thespecific identification methods, reference may be made to the relateddescription above, which will not be described in detail here again.

Based on the reference coordinate system, according to the correspondingrelationship between the measurement items in FIG. 12 and FIG. 13, thecalculation results corresponding to the measurement items may beobtained by calculation.

The measurement sequence automatically generated by the system shown inFIG. 9 may be edited, so as to update the measurement items ormeasurement results. For example, in one embodiment, generating themeasurement sequence according to the feature set and the determinationorder may include the following steps.

First, the image processing unit may automatically generate a presetmeasurement sequence based on the feature set and determination order.The preset measurement sequence may be automatically generated based onthe measurement items inputted by the user in step 12 in FIG. 9.

Thereafter, the preset measurement sequence may be displayed on thedisplay. It may be displayed in a text list or a prompt box.

Then, an editing instruction inputted by the user may be receivedthrough the input/output device. The editing instruction may representan adjustment to the measurement items, or an adjustment to theanatomical features or determination order.

Thereafter, the preset measurement sequence may be updated according tothe editing instruction to obtain the measurement sequence, which may beused to sequentially determine the position of each anatomical featurein the feature set to obtain the measurement instruction.

In the editing mode provided in the embodiment above, after the input iscompleted, the user can enter the editing mode. When the user editsthese inputs, the measurement results may be updated in real time. Whenthe user performs input or editing for the second frame, the system maynot only display in real time the measurement results of the secondframe, but also calculate in real time the changes of certainmeasurement values relative to the first frame, such as the relativechange BND of BSD, the relative change URA of UTA, etc. The editinginstruction in the embodiment above may include at least one of theoperations: 1. adding or deleting the anatomical features in the featureset of the preset measurement sequence; 2. adjusting the determinationorder in the preset measurement sequence; and 3. editing or deleting themeasurement items.

The embodiments shown in FIG. 8 and FIG. 9 and other various embodimentshave mentioned the user's input of the measurement items. The “receivingat least one measurement item inputted by the user input” herein willnot be limited to the user inputting the measurement item one by one,but may also include an input method of obtaining one or moremeasurement items by selecting a measurement mode or a measurementprocess preset by the system.

According to the various embodiments above, a fully automaticmeasurement may be achieved based on the feature set and/or themeasurement sequence. Therefore, in one embodiment, a fully automaticmeasurement method is proposed, which can automatically determine theanatomical features such as the urethrovesical junction (UVJ), theproximal end of urethra, the proximal end of posterior vesical wall andthe lowest point of posterior vesical wall, etc. The detection of theseanatomical features may be performed on the basis of bladdersegmentation tracking. The following uses several special anatomicalfeature detections as examples for illustration.

1. Bladder Segmentation Tracking

The bladder may be segmented to detect other anatomical features usingthe contour of the bladder. FIG. 17 shows an example of bladder contoursegmentation. In FIG. 17, the closed curve indicates the segmentedbladder region. Common segmentation methods may include level setmethod, active contour model method, graph cut method, etc. For dynamiccontinuous image sequences, tracking methods may be used to improveaccuracy and reduce the complexity of frame-by-frame calculations.

2. Urethrovesical Junction

FIG. 20 shows a schematic diagram of the urethrovesical junction(bladder neck) detection. As shown in FIG. 20, the part of the contourof the bladder close to the probe (as shown by the thick yellow part(the thick line frame) in the figure) may be sampled and searched at acertain interval. For each sampled position, the possibility of urethrain different directions within a certain range may be calculated, andthe best position may be determined as the position of the urethra. Thepositions of the urethra and the bladder contour may be returned as theposition value of the bladder neck. The detection method in thisembodiment may be as follows: sampling the part of the contour of thebladder contour (as shown by the thick yellow part (the thick lineframe) in the figure) close to the probe at a certain interval, for eachsampled position, calculating the possibility of urethra in differentdirections within a certain range, determining the best position as theposition of the urethra, and using the position of the urethra and thecontour of the bladder as the position value of the bladder neck. Foreach candidate urethral position, the method for determining the bestcandidate position may be similar to the method for determination of thecentral axis of the symphysis pubis, as described below.

For each candidate urethral position, characteristics related to thestructure of the urethra may be extracted. For example, the pixel valueson the normal lines at both sides of the urethra at an interval alongthe urethral may be selected as the characteristics. The extractedcharacteristics may be inputted to a pre-trained detector and scored toobtain a group of scores. The candidate position with the highest scoremay be selected as the best urethral position.

3. The Lowest Point of Posterior Vesical Wall

The posterior vesical wall may refer to the point closest to the X axis(or the origin of the coordinate system, depending on the calculationmethod of PVD) on the right bladder contour at the urethrovesicaljunction. Since the bladder contour has been located, the rest is tosearch for the point closest to the X axis in a specific region on thebladder contour, as shown in FIG. 22. FIG. 22 schematically shows thedetection of the lowest point of posterior vesical wall and thecalculation of PVD. The positions of the X-axis and the Y-axis may bedetermined by the detected point S and the direction SC (the figureshows the situation where the first Cartesian coordinate system A isused). The position V of the point closest to the X axis of theposterior vesical wall (i.e., the thick yellow part in the figure) maybe obtained according to the tracking result of the bladder contour andthe detection result of the bladder neck. In this case, the Y coordinateof the point V may be the value of PVD.

4. Proximal End of Urethra

When the urethrovesical junction (UVJ) is obtained, the proximal end ofthe urethra may also be detected, i.e., a section of the urethra (forexample, 2 cm) closer to the UVJ may be intercepted.

5. Proximal End of Posterior Vesical Wall

The proximal end of posterior vesical wall may be obtained according tothe positions of the bladder contour and the urethrovesical junction,i.e., a point on the bladder contour close to the urethrovesicaljunction (for example, within 2 cm) may be selected as the proximal endof posterior vesical wall.

Calculation of the Parameters

After the main anatomical features are automatically detected, thecalculation of the parameters may be simple.

The RVA measurement is shown in FIG. 18. The system may use a level setmethod or similar method to automatically detect the contour of thebladder (or only detect the lower half of the contour of the bladder).Furthermore, the system may use a machine learning algorithm toautomatically detect the position of the urethra (the yellow line in thefigure). Based on the contours of the urethra and bladder, the systemmay automatically calculate the RVA from three points N, U and R.

The calculation of UTA is shown in FIG. 19, which schematically shows aschematic diagram of the automatic measurement of the UTA angle. Theposition of the X axis may be determined by the detected two points Cand S, thereby obtaining the direction of the straight line Iperpendicular thereto. The UTA angle is the angle between the urethrarepresented by the ray UN and the straight line I.

The calculation of PVA and PVD is shown in FIG. 20 and FIG. 21. FIG. 21schematically shows the measurement of PVA. The value of PVA (as shownby the red arrow in the figure) may be determined according to thedetected point S, the direction SC and the point V. The size of the PVAis independent of the coordinate system (that is, it is suitable for thefirst and second Cartesian coordinate systems above).

The measurements of PUA and BSD are shown in FIG. 23 and FIG. 24. FIG.23 schematically shows the automatic measurement of BSD. The point U inthe figure is the bladder neck that is automatically detected. Thepositions of the X axis and Y axis may be determined by the detectedpoint S and the direction SC (the figure shows the situation where thefirst Cartesian coordinate system is used). In this case, the Ycoordinate of the point U is the value of BSD. FIG. 24 schematicallyshows the measurement of PUA angle. The value of PUA (as shown by thered arrow in the figure) may be determined according to the detectedpoint S, direction SC and point U. The size of the PUA is independent ofthe coordinate system (that is, it is suitable for the first and secondCartesian coordinate systems above).

In one embodiment, it may also be suitable for the comparativemeasurement of two frames of image for obtaining a dynamically changingmeasurement result. The specific scheme is as follows.

The displayed ultrasound image may include a first frame of image and asecond frame of image. Therefore, the image processing unit may use thefollowing method to obtain the measurement instruction based on theultrasound image and calculate the parameter related to the targettissue according to the measurement instruction to obtain thecalculation result:

the image processing unit may obtain a measurement instruction based onthe first frame of image and calculate the parameter related to thetarget tissue according to the measurement instruction to obtain a firstcalculation result;

the image processing unit may obtain a measurement instruction based onthe second frame of image and calculate the parameter related to thetarget tissue according to the measurement instruction to obtain asecond calculation result;

the image processing unit may calculate a change of the secondcalculation result relative to the first calculation result; and

the image processing unit may output the calculation results and thechange.

These two frames of image may be obtained in the following way:

when multiple frames of ultrasound image are displayed on the display, auser's selection instruction may be received, and the ultrasound imagesmay be obtained according to the selection instruction, where theultrasound images include the first frame of image and the second frameof image, and in one embodiment, the two frames of image may be a restframe image and a valsalva frame image.

Regarding the process of obtaining the first calculation resultaccording to the first frame of image and the process of obtaining thesecond calculation result according to the second frame of image,reference may be made to the proves of obtaining the calculation resultbased on the ultrasound image above. The methods and steps may be partlyor fully the same or similar. For example, by replacing the “ultrasonicimage” in the above steps S230 and S240 with “first frame of image” and“second frame of image”, the process of obtaining the first calculationresult according to the first frame of image and the process ofobtaining the second calculation result according to the second frame ofimage may be obtained.

In addition, after the input is completed, the user may enter the editmode. When the user edits these inputs, the measurement results may beupdated in real time. When the user inputs or edits on the second frameof image, the system may not only display the measurement results of thesecond frame of image in real time, but also calculate the change ofcertain measurement value relative to the first frame of image in realtime, such as the relative change of BSD (i.e., the bladder neck descendBND), the relative change of UTA (i.e., the urethral rotation angleURA), and the relative change of PVD (i.e., the bladder wall descendBWD), etc. When the measurement of the second frame of image iscompleted, if the user edits the input of the first frame, the dynamicchange as shown above will also be updated and displayed in real time.

In the embodiments above, in addition to intelligently assisting manualmeasurement, the ultrasound imaging system may also support fullyautomatic measurement, i.e., all anatomical features may beautomatically detected by algorithms and the values of all parameter maybe automatically obtained according to the positions of the anatomicalfeatures. In the case that the parameter on a single frame of ultrasoundimage is obtained by a fully automatic method, the dynamic change of theparameters may also be automatically obtained accordingly.

In addition, in one embodiment, based on the calculation result of thepelvic floor tissue obtained above, the pelvic floor function may beevaluated to obtain an evaluation level. The International UrinaryControl Association (ICS) has released a quantitative rating system forpelvic floor prolapse procedures, which is referred to as the POP-Qsystem. The POP-Q system grades the pelvic floor prolapse into fivelevels from 0 degree to IV degree through surgical examination. In thepresent embodiment, a quantitative analysis may be performed on theprolapse of the pelvic floor organs using ultrasound examination. Afterthe measurement is completed, the system may obtain a score based on aformula and the measurement results to present the degree or grade ofthe pelvic floor dysfunction. This score may be converted into theequivalent ICS POP-Q score.

Regarding the evaluation of the pelvic floor function, in the presentembodiment, the following methods may be used.

In the first method, the system may provide default evaluation rules,which may be mapped by maximizing the value of PVD under Valsalva, i.e.,

when PVD=1 cm, the equivalent POP-Q is level 1;

when −2 cm <PVD <1 cm, the equivalent POP-Q is level 2; and

when PVD <−2 cm, the equivalent POP-Q is 3 or more.

For example, in one embodiment, the evaluation level may be obtainedbased on the default evaluation rules according to the calculationresult of the parameters. The default evaluation rules here may bemapped by maximizing the calculation results of specific parameterscalculated on a specific frame. The specific frame may include avalsalva frame, and the specific parameter may include the PVD.

In the second method, the user may customize the evaluation rules andformulas with reference to the default rating method. For example, itmay be possible to comprehensively consider the results of both BSD andPVD or change the evaluation threshold. For example, in one embodiment,the evaluation level may be obtained based on the values of BSD and PVDin the calculation results, and may be outputted. In addition, in oneembodiment, the image processing unit may receive the adjustment of theuser to the evaluation rules which are used for determining theevaluation level. Based on the adjusted evaluation rules, the evaluationlevel may be determined according to the calculation results obtained bythe methods above, and be outputted.

In the third method, the system may provide a method based on machinelearning to automatically achieve the comprehensive grading of prolapse,which is described below.

(a) Two-dimensional images, the measurement results of thetwo-dimensional images and the scores to the two-dimensional imagesmanually given by the doctor may be collected offline or online;

(b) The system may automatically perform a mathematical correlationanalysis on the scores given by the doctor, the measurement results andthe images to establish a correlation relationship. There may be manyanalysis methods, such as linear regression method, Kalman filteringmethod, Gaussian process regression method, support vector regressionmethod and other regression analysis methods. Alternatively, the deepneural network method or the like may also be used.

(c) After establishing the correlation relationship, the system mayobtain a rating score comprehensively based on the measurement results.In the case that the user objects to the score, the user can modify thescore manually. The system may further refine the correlationrelationship after receiving the feedback so as to obtain a score thatbetter meets the user's expectations. Anyway, when the ultrasoundimaging system performs the method based on machine learning above, itmay input multiple image samples, the calculation results of theparameters calculated on the image samples and the correspondingevaluation levels into the detector where the mathematical correlationanalysis may be performed thereon to obtain a machine model, andautomatically obtain the evaluation level according to the calculationresults actually obtained on the ultrasound image using the machinemodel. The evaluation levels herein may be presented by number such as0-100, percentage, or quantified staged indexes (such as 1, 2, 3, etc.),etc.

In step S250, the image processing unit may output the calculationresults corresponding to the parameters. The calculation results may beoutputted by print or display.

In one embodiment, when a parameter is calculated, the calculationresult may be displayed immediately. The calculation and result displayof the parameters may increase with the increase of the user input. Thesystem may calculate the parameters one by one and display them in realtime. When the user perform the measurement on the second frame ofimage, the system may additionally calculate the change of the parameterof the second frame relative to the first frame of image in the samecoordinate system, and displays it in real time.

The embodiments above propose convenient and fast parameter measurementmethods based on two-dimensional or three-dimensional ultrasound images,which may be applied to the measurement of pelvic floor parameters. Themethods may automatically establish the measurement coordinate systemand make use of the correlation relationship between the parameters ofthe pelvic floor to minimize the input during the measurement, therebyimproving the measurement efficiency and reducing the measurementerrors. The methods may also calculate the relative change of theparameter between two frames of images according to user needs, andautomatically obtain the dysfunction score or grade of the object beingexamined comprehensively based on these parameters and their relativechanges. The methods may also support online or offline learning thescoring manner of the user so as to achieve automatic scoring.

Through the description of the above embodiments, those skilled in theart will clearly understand that the methods in the embodiments abovemay be implemented by software and a universal hardware platform, orimplemented by hardware. Based on this understanding, the essential partor the part contributing to the existing technology of the technicalsolutions of the present disclosure may be embodied in the form of asoftware product, which may be carried on a non-volatilecomputer-readable storage media (such as ROM, magnetic disk, opticaldisk, hard disk, server cloud space) and include multiple instructionwhich may enable a terminal device (which may be a mobile phone, acomputer, a server, or a network device, etc.) to implement the systemstructures and methods of the embodiments of the present disclosure.

Only several implementations have been described in the embodimentsabove, and the description thereof is relative specific and detailed.However, it cannot be understood as a limitation to the scope of thepresent disclosure. It should be noted that, for those of ordinary skillin the art, several modifications and improvements may be made withoutdeparting from the concept of the present disclosure, which all belongto the protection scope of the present disclosure. Therefore, theprotection scope of the present disclosure shall be determined by to theappended claims.

What is claimed is:
 1. A method for measuring a parameter in anultrasound image, comprising: obtaining a pelvic ultrasound image,wherein the pelvic ultrasound image is acquired by receiving ultrasoundechoes from a pelvic floor tissue with an ultrasound probe and containsan area representing the pelvic floor tissue; displaying the pelvicultrasound image; determining a position of an inferoposterior margin ofsymphysis pubis in the pelvic ultrasound image; determining a centralaxis of symphysis pubis in the pelvic ultrasound image; determining anaxis that passes through the determined position of the inferoposteriormargin of symphysis pubis and is at an angle of 135 degree with respectto the determined central axis of symphysis pubis; determining aposition of a bladder neck in the pelvic ultrasound image; andcalculating a distance from the determined position of the bladder neckto the determined axis to obtain a value of a bladder neck-symphysealdistance.
 2. The method of claim 1, wherein determining the position ofthe inferoposterior margin of symphysis pubis in the pelvic ultrasoundimage comprises: automatically identifying the position of theinferoposterior margin of symphysis pubis in the pelvic ultrasoundimage; or detecting a click operation of a user on an area correspondingto the inferoposterior margin of symphysis pubis in the pelvicultrasound image to obtain the position of the inferoposterior margin ofsymphysis pubis in the pelvic ultrasound image.
 3. The method of claim1, wherein determining the central axis of symphysis pubis in the pelvicultrasound image comprises: automatically identifying the central axisof symphysis pubis in the pelvic ultrasound image; or detecting a clickoperation of a user on an area corresponding to the central axis ofsymphysis pubis in the pelvic ultrasound image to obtain the centralaxis of symphysis pubis in the pelvic ultrasound image.
 4. The method ofclaim 1, wherein determining the position of the bladder neck in thepelvic ultrasound image comprises: automatically identifying theposition of the bladder neck in the pelvic ultrasound image; ordetecting a click operation of a user on an area corresponding to thebladder neck in the pelvic ultrasound image to obtain the position ofthe bladder neck in the pelvic ultrasound image.
 5. The method of claim1, further comprising: determining a position of a proximal urethra inthe pelvic ultrasound image; and calculating an angle between a lineconnecting the determined position of the bladder neck and thedetermined position of the proximal urethra in the pelvic ultrasoundimage and a line perpendicular to the determined axis to obtain a valueof a urethral tilt angle.
 6. The method of claim 5, wherein determiningthe position of the proximal urethra in the pelvic ultrasound imagecomprises: automatically identifying the position of the proximalurethra in the pelvic ultrasound image; or detecting a click operationof a user on an area corresponding to the proximal urethra in the pelvicultrasound image to obtain the position of the proximal urethra in thepelvic ultrasound image.
 7. The method of claim 5, further comprising:determining a position of a proximal end of posterior vesical wall inthe pelvic ultrasound image; and calculating an angle between the lineconnecting the determined position of the bladder neck and thedetermined position of the proximal urethra and a line connecting thedetermined position of the bladder neck and the determined position ofthe proximal end of posterior vesical wall in the pelvic ultrasoundimage to obtain a value of a posterior urethrovesical angle.
 8. Themethod of claim 7, wherein determining the position of the proximal endof posterior vesical wall in the pelvic ultrasound image comprises:automatically identifying the position of the proximal end of posteriorvesical wall in the pelvic ultrasound image; or detecting a clickoperation of a user on an area corresponding to the proximal end ofposterior vesical wall in the pelvic ultrasound image to obtain theposition of the proximal end of posterior vesical wall in the pelvicultrasound image.
 9. The method of claim 1, further comprising:calculating an angle between the determined central axis of symphysispubis and a line connecting the determined position of theinferoposterior margin of symphysis pubis and the determined position ofthe bladder neck in the pelvic ultrasound image to obtain a value of apubourethral angle.
 10. The method of claim 1, further comprising:determining a position of a lowest point of posterior vesical wall inthe pelvic ultrasound image; and calculating an angle between thedetermined central axis of symphysis pubis and a line connecting thedetermined position of the inferoposterior margin of symphysis pubis andthe determined position of the lowest point of posterior vesical wall toobtain a value of a pubovesical angle.
 11. The method of claim 10,wherein determining the position of the lowest point of posteriorvesical wall in the pelvic ultrasound image comprises: automaticallyidentifying the position of the lowest point of posterior vesical wallin the pelvic ultrasound image; or detecting a click operation of a useron an area corresponding to the lowest point of posterior vesical wallin the pelvic ultrasound image to obtain the position of the lowestpoint of posterior vesical wall in the pelvic ultrasound image.
 12. Themethod of claim 1, further comprising: determining a position of alowest point of posterior vesical wall in the pelvic ultrasound image;and calculating a distance from the determined position of the lowestpoint of posterior vesical wall to the determined axis to obtain a valueof a pubovesical distance.
 13. The method of claim 1, furthercomprising: generating an anatomical schematic diagram of the pelvicfloor tissue based on knowledge of tissue anatomy; displaying theanatomical schematic diagram; and prompting the position to bedetermined on the anatomical schematic diagram.
 14. A method formeasuring a parameter in an ultrasound image, comprising: obtaining apelvic ultrasound image, wherein the pelvic ultrasound image is acquiredby receiving ultrasound echoes from a pelvic floor tissue with anultrasound probe and contains an area representing the pelvic floortissue; displaying the pelvic ultrasound image; determining a positionof an inferoposterior margin of symphysis pubis in the pelvic ultrasoundimage; determining a central axis of symphysis pubis in the pelvicultrasound image; determining an axis that passes through the determinedposition of the inferoposterior margin of symphysis pubis and is at anangle of 135 degree with respect to the determined central axis ofsymphysis pubis; determining a position of a lowest point of posteriorvesical wall in the pelvic ultrasound image; and calculating a distancefrom the determined position of the lowest point of posterior vesicalwall to the determined axis to obtain a value of a pubovesical distance.15. The method of claim 14, further comprising: calculating an anglebetween the determined central axis of symphysis pubis and a lineconnecting the determined position of the inferoposterior margin ofsymphysis pubis and the determined position of the lowest point ofposterior vesical wall in the pelvic ultrasound image to obtain a valueof a pubovesical angle.
 16. An ultrasound imaging system, comprising: aprobe; a transmitting circuit that is configured to excite the probe totransmit an ultrasonic beam to a pelvic floor tissue; a receivingcircuit that is configured to receive ultrasonic echoes of theultrasonic beam through the probe to obtain ultrasonic echo signals; aprocessor that is configured to: obtain a pelvic ultrasound imageaccording to the ultrasound echo signals, wherein the pelvic ultrasoundimage contains an area representing the pelvic floor tissue; determine aposition of an inferoposterior margin of symphysis pubis in the pelvicultrasound image; determine a central axis of symphysis pubis in thepelvic ultrasound image; determine an axis that passes through thedetermined position of the inferoposterior margin of symphysis pubis andis at an angle of 135 degree with respect to the determined central axisof symphysis pubis; determine a position of a bladder neck in the pelvicultrasound image; and calculate a distance from the determined positionof the bladder neck to the determined axis to obtain a value of abladder neck-symphyseal distance; and a display that is configured todisplay the pelvic ultrasound image.
 17. The system of claim 16, whereinthe processor is further configured to: determine a position of aproximal urethra in the pelvic ultrasound image; and calculate an anglebetween a line connecting the determined position of the bladder neckand the determined position of the proximal urethra in the pelvicultrasound image and a line perpendicular to the determined axis toobtain a value of a urethral tilt angle.
 18. The system of claim 17,wherein the processor is further configured to: determine a position ofa proximal end of posterior vesical wall in the pelvic ultrasound image;and calculate an angle between the line connecting the determinedposition of the bladder neck and the determined position of the proximalurethra and a line connecting the determined position of the bladderneck and the determined position of the proximal end of posteriorvesical wall in the pelvic ultrasound image to obtain a value of aposterior urethrovesical angle.
 19. The system of claim 16, wherein theprocessor is further configured to: calculate an angle between thedetermined central axis of symphysis pubis and a line connecting thedetermined position of the inferoposterior margin of symphysis pubis andthe determined position of the bladder neck in the pelvic ultrasoundimage to obtain a value of a pubourethral angle.
 20. The system of claim19, wherein the processor is further configured to: determine a positionof a lowest point of posterior vesical wall in the pelvic ultrasoundimage; and calculate an angle between the determined central axis ofsymphysis pubis and a line connecting the determined position of theinferoposterior margin of symphysis pubis and the determined position ofthe lowest point of posterior vesical wall to obtain a value of apubovesical angle.